Capsule and Seals for an Electronic Cigarette

ABSTRACT

A capsule for an electronic cigarette has a first end configured to engage with an electronic cigarette device, a second end arranged as a mouthpiece portion having a vapour outlet, a liquid store configured to contain a liquid to be vaporized; a vaporizing housing arranged to house a heating element and a fluid transfer element, arranged to deliver liquid from the liquid store to the heating element, the heating element being configured to vaporize the received liquid and generate a vapor; a main vapor flow channel extending between the vaporizing housing and the mouthpiece to allow the generated vapor to flow from the vaporizing housing to the mouthpiece; an airflow passageway extending between the first end and the vaporizing housing; where the vaporizer housing includes at least one aperture located within a sidewall of the vaporizer housing, the aperture forming part of the airflow passageway.

FIELD OF INVENTION

The present invention relates to personal vaporizing devices, such as electronic cigarettes. In particular, the invention relates to capsules having seals, the capsules to be used with an electronic cigarette.

BACKGROUND

Electronic cigarettes are an alternative to conventional cigarettes. Instead of generating a combustion smoke, they vaporize a liquid, which can be inhaled by a user. The liquid typically comprises an aerosol-forming substance, such as glycerin or propylene glycol that creates the vapor. Other common substances in the liquid are nicotine and various flavorings.

The electronic cigarette is a hand-held inhaler system, comprising a mouthpiece section, a liquid store, a power supply unit. Vaporization is achieved by a vaporizer or heater unit which typically comprises a heating element in the form of a heating coil and a fluid transfer element. The vaporization occurs when as the heater heats up the liquid in the wick until the liquid is transformed into vapor. The electronic cigarette may comprise a chamber in the mouthpiece section, which is configured to receive disposable consumables in the form of capsules. Capsules comprising the liquid store and the vaporizer are often referred to as “cartomizers”.

Conventional cigarette smoke comprises nicotine as well as a multitude of other chemical compounds generated as the products of partial combustion and/or pyrolysis of the plant material. Electronic cigarettes on the other hand deliver primarily an aerosolized version of an initial starting e-liquid composition comprising nicotine and various food safe substances such as propylene glycol and glycerine, etc., but are also efficient in delivering a desired Nicotine dose to the user. The aerosol generated by an electronic cigarette is generally referred to as a vapor.

In order to ensure that sufficient vapor is generated, to provide the user with a satisfying user experience, it is important to ensure that the liquid is prevented from leaking from the liquid store and into the capsule or electronic cigarette.

Furthermore, liquid leaking from the liquid store may travel to the power supply, or other electronics, and could cause the electrical circuitry to short out. This is dangerous and could potentially lead to injury of a user.

It is an object of the present invention to reduce the likelihood of liquid leaking from the liquid store.

SUMMARY OF INVENTION

According to an aspect of the present invention there is provided a capsule for an electronic cigarette, the capsule having a first end configured to engage with an electronic cigarette device and a second end arranged as a mouthpiece portion having a vapour outlet. The capsule comprises a liquid store configured to contain a liquid to be vaporized and a vaporizing housing arranged to house a heating element and a fluid transfer element, wherein the fluid transfer element is arranged to deliver liquid from the liquid store to the heating element, the heating element being configured to vaporize the received liquid and generate a vapor. The capsule further comprises a main vapor flow channel extending between the vaporizing housing and the mouthpiece to allow the generated vapor to flow from the vaporizing housing to the mouthpiece. The capsule further comprises an airflow passageway extending between the first end and the vaporizing housing. The vaporizer housing comprises at least one aperture located within a sidewall of the vaporizer housing, the aperture forming part of the airflow passageway.

The airflow passageway allows air drawn from outside of the capsule to flow into the vaporizing housing. This configuration provides an air entry point, in the form of the at least one aperture, which is located in a side portion of the vaporizer housing such that air can flow directly into an internal cavity of the vaporizer housing and to the fluid transfer element.

Preferably, the aperture is positioned at distance above a lower rim of the vaporizing housing at the first end of the capsule. The aperture is also positioned at a distance below an upper rim of the vaporizing housing at the second end of the capsule.

Preferably, the vaporizer housing comprises a pair of apertures positioned at opposite sidewalls of the vaporizer housing. As a result, air flow from both sides into the internal cavity to the fluid transfer element.

The capsule may further comprise a first seal comprising a pair of shoulder portions. The vaporizer housing may comprise a pair of cut-outs. The pair of shoulder portions and the pair of cutouts may be configured to cooperate with each other such that the fluid transfer element is held between the pair of shoulder portions and the pair of cutouts. The seal and the vaporizer housing may therefore be considered as being in cooperation with each other such that the fluid transfer element is held between the seal and the vaporizer housing.

Preferably, the fluid transfer element is arranged to be compressed between the pair of shoulder portions and the pair of cutouts. This may help apply pressure to the fluid transfer element. The fluid transfer element is therefore tightly held between the seal and the vaporizer housing, helping prevent fluid from leaking from the fluid transfer element into the capsule. Additionally, by having the seal cooperate with the vaporizer housing, the seal is able to apply a sufficient compressive force to the fluid transfer element when the fluid transfer element is held between the pair of shoulder portions and the pair of cutouts, helping prevent leakage from around the seal.

When referring to the fluid transfer element being held between the pair of shoulder portions and the pair of cutouts, we do not mean that the fluid transfer element is entirely located between the pair of shoulder portions and the pair of cutouts. Instead, the fluid transfer element may extend beyond either the first shoulder portion, second shoulder portion, or both shoulder portions. The fluid transfer element is generally held centrally between the first and second shoulder portions. In this case, there will be a substantially equal extension of the fluid transfer portion beyond both the first and second shoulder portions. Alternatively, in some examples, the fluid transfer element may be positioned off-center between the first and second shoulder portions such that an extension of the fluid transfer element beyond one of the shoulder portions is greater than an extension of the fluid transfer element beyond the other shoulder portion.

Preferably, the fluid transfer element is arranged to be compressed in a radial direction of the fluid transfer element between the pair of shoulder portions and the pair of cutouts. The tight fit achieved by having surfaces of both the shoulder portions and cutouts which cooperate with the ends of the fluid transfer element improves the ability of the seal to apply a suitable pressure to the fluid transfer element. By compressing the fluid transfer element, the liquid flow from the liquid store to the vaporization chamber is guided through the fluid transfer element and so leakage around the fluid transfer element is reduced.

Each shoulder portion may comprise a substantially curved surface. Each curved surface preferably has a curvature which substantially corresponds to a curvature of an external surface of the fluid transfer element. Having curved surfaces that substantially correspond to each other helps ensure a close fit between two neighboring surfaces when the capsule is constructed. This is important for preventing leakage because any gaps that are formed between or exist between components create a potential pathway for liquid to travel along and leak from the capsule.

In some cases, the fluid transfer element may be substantially U-shaped, allowing for a tight, or snug, fit between the vaporizer housing and the seal in order to further reduce the chance of leakage.

Preferably, the capsule further comprises a pair of posts arranged to provide an electrical connection between the main body and the capsule. An interface may be formed between the vaporizer housing and the pair of posts.

The heating element may comprise first and second ends. Preferably, the first and second ends are located at the interface between the vaporizer housing and the pair of posts. In other words, the first and second ends of the heating elements may be positioned between the vaporizer housing and the pair of posts. Thus, the first and second ends of the heating element are held between the vaporizer housing and the pair of posts at the interface between the vaporizer housing and the pair of posts.

In some cases, the first and second ends of the heating element may be compressed between the vaporizer housing and the pair of posts. at the interface.

The first and second ends of the heating element may form lead wires. The lead wires may be attached to a heating wire of the heating element. The first and second ends of the heating element, e.g. lead wires, may be considered to be clamped, or squeezed, between the vaporizer housing and the pair of posts. Advantageously, this clamping arrangement helps ensure that the heating element is held firmly and securely in place within the capsule. Additionally, and advantageously, by clamping the first and second ends of the heating element between the vaporizer housing and the pair of posts, the first and second ends of the heating element are prevented from coming in to contact with electrical components present in the electronic cigarette device, when the capsule is connected to the electronic cigarette device, reducing the likelihood of any liquid which may be present on the heating element causing potential short circuits.

The capsule may further comprise a first holder arranged to retain the vaporizer housing. The first holder may therefore be considered as receiving the vaporizer housing, and may be configured to act as a support structure for the vaporizer housing. Providing a support structure for the vaporizing housing advantageously helps ensure that the vaporizing housing is held firmly and in its correct position within the capsule.

Preferably, the capsule comprises a second holder configured to receive the first holder. An interface may be formed between the first and second holders.

Typically, the second holder may comprise at least one airflow inlet arranged to allow intake air to flow into the vaporizing housing. The airflow inlet forms part of the airflow passage way. Providing an airflow passageway which extends into the vaporizer chamber helps ensures that intake air is delivered to the appropriate part of the capsule i.e. the vaporizer chamber.

According to another aspect there is provided an electronic cigarette comprising a main body and a capsule wherein the main body comprises a power supply unit, electrical circuitry, and a capsule seating configured to connect with the capsule. The capsule comprises a liquid store configured to contain a liquid to be vaporized and a vaporizing housing arranged to house a heating element and a fluid transfer element, wherein the fluid transfer element is arranged to deliver liquid from the liquid store to the heating element, the heating element being configured to vaporize the received liquid and generate a vapor. The capsule also comprises a main vapor flow channel extending between the vaporizing housing and the mouthpiece to allow the generated vapor to flow from the vaporizing housing to the mouthpiece. The capsule further comprises an airflow passageway extending between the first end and the vaporizing housing. The vaporizer housing comprises at least one aperture located within a sidewall of the vaporizer housing, the aperture forming part of the airflow passageway.

The electronic cigarette may be configured to connect with a capsule according to any of the previously described capsules.

BRIEF DESCRIPTION OF DRAWINGS

Embodiments of the invention will now be described by way of example of with reference to the accompanying drawings in which:

FIG. 1A is a schematic perspective view of an electronic cigarette;

FIG. 1B is a schematic perspective side view of the electronic cigarette of FIG. 1A;

FIG. 10 is a schematic cross-sectional view of the electronic cigarette of FIGS. 1A and 1B;

FIG. 2A is a schematic perspective view of the electronic cigarette in FIGS. 1A and 1B, wherein the capsule has been disconnected from the electronic cigarette;

FIG. 2B is a schematic perspective view of a capsule seating;

FIG. 3A is a schematic view of a capsule;

FIG. 3B is a schematic side view of the capsule of FIG. 3A;

FIG. 4 is an exploded schematic view of a capsule;

FIG. 5 is an exploded schematic view of a capsule;

FIG. 6 is a schematic cross-sectional view of FIG. 5 in an assembled state;

FIG. 7 is a schematic sideways cross-sectional view of FIG. 5 in an assembled state;

FIG. 8 is a schematic cross-sectional view of a capsule;

FIG. 9A is a bottom-up view of a part of a capsule;

FIG. 9B is a bottom-up view of another part of a capsule; and

FIG. 9C is a bottom-up view of another part of a capsule.

SPECIFIC DESCRIPTION

As used herein, the term “inhaler” or “electronic cigarette” may include an electronic cigarette configured to deliver an aerosol to a user, including an aerosol for smoking. An aerosol for smoking may refer to an aerosol with particle sizes of 0.5-7 microns. The particle size may be less than 10 or 7 microns. The electronic cigarette may be portable.

Referring to the drawings and in particular to FIGS. 1A to 10, 2A and 2B, an electronic cigarette 2 for vaporizing a liquid L is illustrated. The electronic cigarette 2 can be used as a substitute for a conventional cigarette. The electronic cigarette 2 has a main body 4 comprising a power supply unit 6, electrical circuitry 8 and a capsule seating 12. The capsule seating 12 is configured to receive removable capsules 16 comprising a vaporizing liquid L. The liquid L may comprise an aerosol-forming substance such as propylene glycol and/or glycerol and may contain other substances such as nicotine and acids. The liquid L may also comprise flavorings such as e.g. tobacco, menthol or fruit flavor.

The capsule seating 12 is preferably in the form of a cavity configured to receive the capsule 16. The capsule seating 12 is provided with a connection portion 21 configured to hold the capsule 16 firmly to the capsule seating 12. The connection portion 21 could for instance be an interference fit, a snap fit, a screw fit, a bayoneted fit or a magnetic fit. The capsule seating 12 further comprises a pair of electrical connectors 14 configured to engage with corresponding power terminals 45 on the capsule 16.

As best seen in FIGS. 2A and 2B, the capsule 16 comprises a housing 18, a liquid store 32, a vaporizing unit 34 and power terminals 45. The housing 18 has a mouthpiece portion 20 provided with a vapor outlet 28. The mouthpiece portion 20 may have a tip-shaped form to correspond to the ergonomics of the user's mouth. On the opposite side of mouthpiece portion 20, another connection portion 22 is located. The mouthpiece connection portion 22 is configured to connect with the connection portion 21 in the capsule seating 12. The connection portion 22 on the capsule 16 may comprise a metallic plate, configured to magnetically connect to a magnetic surface in the capsule seating 12. The capsule housing 18 may be in a transparent material, whereby the liquid level of the capsule 16 is clearly visible to the user. The housing 18 may be formed in a polymeric or plastic material, such as polyester.

As seen in FIG. 4 , the capsule 16 may be assembled from a plurality of different parts. However, the illustrated embodiment is schematic and it is also possible to combine some of the parts to single units which will be apparent to a person skilled in the art. The present configuration of a plurality of different parts enables an efficient assembly of the capsule 16.

The capsule housing 18 may be formed from a top housing 18 a and a bottom housing 18 b or a base 18 b. The parts can be assembled together by a friction fit between the top housing 18 a and a bottom housing 18 b. Additionally, or alternatively, the top housing 18 a and a bottom housing 18 b can be joined together by ultrasonic welding. Optionally, as illustrated in the figure, the top housing 18 a may comprise the mouthpiece portion 20 as a separate part that is assembled to the top housing 18 a of the capsule.

As shown in FIG. 3A together with FIG. 4 , the vaporizing chamber 30 is located at the opposite distal end of the capsule 16 to the mouthpiece portion 20 and houses the vaporizing unit 34. From the vaporizing chamber 30 to the vapor outlet 28 in the mouthpiece portion 20, a main vapor channel 24 is defined which may have a tubular cross-section. The main vapor channel 24 can be formed from a tube or chimney 24 which extends distally away from the mouthpiece where it may be sealingly connected to the vaporizing chamber 30. Conveniently the tube or chimney 24 can formed integrally with the top housing. This part can for instance be produced by injection molding or molding. Once the tube or chimney 24 is connected to the vaporizing chamber 30, the main vapor channel is formed.

The vaporizing chamber 30 is surrounded by the liquid store 32. It is sealed such that it only receives liquid through a liquid delivery channel 33, receives intake air from an air inlet 35, and delivers vapor through the main vapor channel (via tube or chimney 24). To this effect, the vaporizing unit 34 is accommodated inside a tubular vaporizer housing 40.

In order to provide an optimal user experience when using the electronic cigarette 2 for, it is important to prevent liquid leaking from the liquid store 32 and into the capsule 16. It is also important to prevent liquid leaking from the capsule 16 and into the capsule seating 12. There are a number of potential leakage points that have been identified in the electronic cigarette 2 which need to be effectively sealed against the liquid. Firstly, liquid may leak from around the fluid transfer element 38 into the main vapor channel and along the main flow path through the capsule 16.

Liquid may also leak from the liquid store 32 or from the fluid transfer element 38 into the air inlet 35 and out through the capsule 16 and potentially into the capsule seating 12 in which the electrical circuitry 8 is housed. This could potentially cause the electrical circuitry 8 to short circuit.

There is also a risk that liquid leaks from any gaps that may be present in the vaporizing unit 34, between the heating element 36, the fluid transfer element 38, and the liquid store 32.

In order to reduce the risk of leakage from the capsule 16, the capsule 16 comprises a sealing assembly 44. The sealing assembly comprises a seal 50, a first holder 60 which may also be referred to as an isolation holder 60, and a second holder 70 which may also be referred to as a heating holder 70. The sealing assembly 44 is configured to surround the vaporizer housing 40 and the vaporizer unit 34, as can be seen in FIG. 5 .

The vaporizer housing 40 has an upper rim 42 a and a lower rim 42 b, the upper rim 42 a being in contact with the seal 50, which may also be referred to as a gasket 50, and the lower rim 42 b being in contact with the isolation holder 60. The seal 50 is typically made of a resilient or compressible material, for example silicon, to minimize leakage through the connections. The heating holder 70 is configured to seal around the outer circumference of the tubular vaporizer housing 40, as can be seen in FIG. 5 .

The vaporizing unit 34 comprises a heating element 36 and a fluid transfer element 38. The fluid transfer element 38 is configured to transfer the liquid L by capillary action from the liquid store 32 to the heating element 36. The fluid transfer element 38 can be a fibrous or porous element such as a wick made from twined cotton or silica. Alternatively, the fluid transfer element 38 can be any other suitable porous element.

The vaporizing chamber 30 is fluidly connected to the liquid store 32 by the fluid transfer element 38. Hence, the liquid inlet to the vaporization chamber 30 is provided solely through the fluid transfer element 38 and through the passages 33 formed from the porous structures of the fluid transfer element 38.

The fluid transfer element 38 has a first end 38 a and a second end 38 b. The fluid transfer element 38 is provided with a substantially elongated main body portion, and the first and second ends are provided substantially perpendicularly to the main body portion, as shown in FIG. 5 . In other words, the fluid transfer element 38 takes the form of a rectangular “u”-shape. In use, the first and second ends of the fluid transfer element 38 extend in a downward direction, substantially parallel to a longitudinal axis of the capsule 16, while the main body portion of the fluid transfer element 38 extends in a substantially horizontal direction, substantially perpendicular to a longitudinal axis of the capsule 16. This means that, typically, the fluid transfer element 38 is arranged with its longitudinal extension perpendicular or traverse to the longitudinal direction of the cartridge 16. The fluid transfer element 38 has a liquid uptake portion 39 a located inside the liquid store 32 and a liquid delivery portion 39 b in contact with the heating element 36 inside the vaporization chamber 30.

The liquid uptake portion 39 a corresponds to the first end 38 a and the second end 38 b of the fluid transfer element 38. The heating element 36 is positioned on the liquid delivery portion 39 b of the fluid transfer element 38. The liquid delivery portion 39 b corresponds to the center portion of the fluid transfer element 38. That is to say, the delivery portion 39 b corresponds to the main body portion of the fluid transfer element 38. As shown in the figures, the heating element 36 is provided on the outside circumference of the main body portion of the fluid transfer element 38.

The vaporizer housing 40 is further provided with a pair of cutouts 48 through which the first and the second ends 38 a, 38 b of the fluid transfer element 38 are received. The seal 50 is located in the connection between the vaporization chamber 30 and the fluid transfer element 38. The seal 50 has a contact surface S1 that corresponds to the shape of the upper rim 42 a of the vaporizer housing 40. The seal 50 is further provided with an aperture 51 through which the vapor can flow from the vaporization chamber 30 to the main vapor flow channel.

As shown in FIG. 5 , the seal 50 comprises a pair of radially extending shoulder portions 52, which extend in a direction substantially perpendicular to a longitudinal axis of the electronic cigarette 2. The shoulder portions 52 are generally curved in shape, for example taking the form of an arc or semi-circle as can be seen for example in FIGS. 5 and 9A, and having an inwardly curving surface 52 a, which may be thought of as a concave surface 52 a, and an outwardly curving surface 52 b, which may be thought of as a convex surface 52 b. When the electronic cigarette 2 is held in a vertical position, the concave surface 52 a is located below the convex surface 52 b such that the shoulder portions may be described as substantially “n”-shaped.

The inwardly curved surface 52 a of the shoulder portions 52 is shaped to correspond to the shape of the first and second ends 38 a, 38 b of the fluid transfer element 38. In other words, the curvature of the first and second ends of the fluid transfer element 38 substantially corresponds to the curvature of the inwardly curving surface 52 a of the shoulder portions 52. Having curved surfaces that substantially corresponds to each other ensures a close fit between the two neighboring surfaces, which in this case are the surface of the fluid transfer element 38 and the concave surface of the shoulder portion 52, when the electronic cigarette 2 is constructed. This is important for preventing leakage, as any gaps or “wiggle room” created through loose fitting parts creates a potential pathway for liquid to travel along and leak from the capsule 16.

The shoulder portions 52 are configured to press against, i.e. apply pressure to, the fluid transfer element 38 when the capsule 16 is assembled. The seal 50 is configured to compress the fluid transfer element 38 in the radial direction of the fluid transfer element 38. The tight fit achieved by having complementary adjacent surfaces of the ends of the fluid transfer element 38 and the concave surfaces 52 a of the seal 50 improves the ability of the seal 50 to apply a suitable pressure to the fluid transfer element 38. That is to say, by having the seal 50 shaped to cooperate with the shape of the surface of the fluid transfer element, when they are in contact with each other, the seal 50 is able to apply a sufficient compressive force to the fluid transfer element 38 when the fluid transfer element 38 is held within the cutouts 48, between the seal 50 and the vaporizer housing 40, helping prevent leakage from around the seal. By compressing the fluid transfer element 38, the liquid flow from the liquid store 32 to the vaporization chamber 30 is guided through the fluid transfer element 38. Hence, leakage around the fluid transfer element 38 is prevented.

When assembled, the fluid transfer element 38 is tightly held between the seal 50 and the vaporizer chamber 40, within the cutouts 48 in the vaporizer housing 40, as shown in FIG. 6 . The seal 50 and the vaporizer housing 40 cooperate with each other in order to clamp the fluid transfer element 38 between these two components and retain it within the cutouts 48. This configuration helps prevent fluid from leaking from the fluid transfer element 38 into the electronic cigarette 2.

As shown in FIGS. 5 and 6 , the seal 50 comprises a base portion 50 c which acts, in combination with the main body of the seal 50, to house components of the capsule such as the vaporizer housing 40. The main body of the seal can therefore be thought of as defining an internal cavity portion. The base portion 50 c is also configured to receive, and retain, the holder 60, also known as the isolation holder 60, such that the holder 60 is located within the base portion 50 c. The holder 60 is for receiving the vaporizer housing 40, acting as a support for the vaporizer housing 40, as shown in FIG. 6 . Specifically, the lower rim 42 b of the vaporizer housing 40 is received by the holder 60 so that the vaporizer housing 40 is held firmly and in its correct position within the capsule 16.

The heating holder 70 is arranged to be connected to the base portion 50 c of the seal 50 for example by a push fit or snap fit connection. Both the heating holder 70 and the isolation holder 60 comprise a pair of through holes 62, 72 or apertures 62, 72 as shown in FIGS. 9B and 9C. These apertures 62, 72 are arranged to receive a pair of posts 80, for example as shown in FIG. 8 . These posts 80 ensure that the components are connected together and do not come apart from each other. Furthermore, these posts 80 help ensure that the first and second ends 36 a, 36 b of the heating element are held sufficiently tightly between the isolation holder 60 and the heating holder 70.

As well as helping secure the components together, the posts 80 also act as electrical connectors for the transfer of current between the capsule seating 12 and the capsule 16. The posts 80 are therefore made of any suitable material which is able to transfer current, for example a metal such as copper.

The holder 60 is itself received and retained by the heating holder 70, as shown in FIG. 6 , such that an interface is formed between a surface of the isolation holder 60 and the heating holder 70. This interface also corresponds to an interface formed between the surface of the isolation holder 60 and the posts 80. The heating element has first and second ends 36 a, 36 b which are held between the isolation holder 60 and the posts 80 at the interface between the isolation holder 60 and the posts 80. The first and second ends 36 a, 36 b of the heating element are therefore clamped, or squeezed, between the isolation holder 60 and the posts 80. This ensures that the heating element 36 is held firmly in place within the capsule 16. Additionally, and advantageously, by clamping the first and second ends 36 a, 36 b of the heating element between the isolation holder 60 and the posts 80, the ends of the heating element 36 are prevented from coming in to contact with the electrical circuitry 8 in the main body 4. This configuration reduces the likelihood of any unwanted liquid which may be present in the heating element 36 to come into contact with the electrical components which can leads to short circuits.

As sown in FIG. 9C, in addition to the pair of apertures 72 the heating holder 70 comprises a pair of air holes 71, in the form of two through bores passing through the main body of the heating holder 70, arranged to allow air to flow into the vaporizing chamber 30 via the air inlet 35 in the vaporizer unit 34, as shown in FIG. 7 .

Similarly, the vaporizer housing 40 comprises a pair of air holes 41, in the form of two through bores passing through the main body of the vaporizer housing 40. The pair of air holes 41 extends through the side walls of the vaporizer housing 40, as shown in FIGS. 5 and 7 . The air holes 41 are arranged to allow air to flow into the vaporizing chamber 30. Both pairs of air holes 62, 71 therefore comprise part of the airflow passageway. The capsule therefore comprises an airflow passageway in which air flows along an external side of the vaporizer housing 40 and a main vapor channel 24 in which vapor as generated in vaporizer unit flows along an internal portion of the vaporizer housing 40, as show in FIG. 7 .

As shown, for example, in FIG. 5 , the heating element 36, comprises a heating wire 36, which is wound around the fluid transfer element 38 and so takes the form of a heating coil. The heating wire 36 is configured to heat the fluid transfer element 38 by resistive heating. Typically, the heating element 36 is not directly connected to the electrodes 80 but is instead indirectly connected to the electrodes 80 via a plurality of lead wires, which act as an intermediate between the heating element 36 and the electrodes 80. The heating element 36 is connected to the lead wires generally near the fluid transfer element 38. The heating element 36 therefore comprises the heating wire 36 (also known as a heating coil) and lead wires, typically two lead wires. The heating wire 36 is generally connected to each lead wire by spot welding or clipper. In this description, the lead wires, specifically first and second lead wires, of the heating element may also be referred to as first and second ends of the heating element. In an advantageous embodiment, the material of the heating wire 36 can be titanium. Titanium has a steep resistance to temperature curve in comparison with e.g. stainless steel or nickel. Hence, the resistance of the heating wire 36 increases relatively rapidly with an increasing coil temperature. However, other materials such as Stainless steel, Nickel, Chrome or Aluminium or alloys thereof are also possible.

The main body 4 is configured via the posts 80 to supply power to the heating element 36 of the capsule and to control the overall operation of the vaporization. The main body 4 can be configured as a compact device in comparison to most prior art electronic cigarettes. Preferably, the device is provided with a dimension that it will fit into the palm of a hand.

The electrical circuitry 8 of the main body 4 is configured to operate the electronic cigarette 2 and may comprise a flow sensor 10 or a manual activation switch, a memory 11 and a controller 13. The electrical circuitry 8 may advantageously be grouped onto a main printed circuit board.

The skilled person will realize that the present invention by no means is limited to the described exemplary embodiments. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage. Moreover, the expression “comprising” does not exclude other elements or steps. Other non-limiting expressions include that “a” or “an” do not exclude a plurality and that a single unit may fulfill the functions of several means. Any reference signs in the claims should not be construed as limiting the scope. Finally, while the invention has been illustrated in detail in the drawings and in the foregoing description, such illustration and description is considered illustrative or exemplary and not restrictive; the invention is not limited to the disclosed embodiments. 

1. A capsule for an electronic cigarette, the capsule having a first end configured to engage with an electronic cigarette device and a second end arranged as a mouthpiece portion having a vapour outlet, the capsule further comprising: a liquid store configured to contain a liquid to be vaporized; a vaporizer housing arranged to house a heating element and a fluid transfer element, wherein the fluid transfer element is arranged to deliver liquid from the liquid store to the heating element, the heating element being configured to vaporize the received liquid and generate a vapor; a main vapor flow channel extending between the vaporizer housing and the mouthpiece portion to allow the generated vapor to flow from the vaporizer housing to the mouthpiece portion; an airflow passageway extending between the first end and the vaporizer housing; wherein the vaporizer housing comprises at least one aperture located within a sidewall of the vaporizer housing, the at least one aperture forming part of the airflow passageway.
 2. The capsule according to claim 1, further comprising a first seal comprising a pair of shoulder portions.
 3. The capsule according to claim 2, wherein the vaporizer housing comprises a pair of cutouts.
 4. The capsule according to claim 3, wherein the pair of shoulder portions and the pair of cutouts are configured to cooperate with each other such that the fluid transfer element is held between the pair of shoulder portions and the pair of cutouts.
 5. The capsule according to claim 4, wherein the fluid transfer element is arranged to be compressed between the pair of shoulder portions and the pair of cutouts.
 6. The capsule according to claim 4, wherein the fluid transfer element is arranged to be compressed in a radial direction of the fluid transfer element between the pair of shoulder portions and the pair of cutouts.
 7. The capsule according to claim 2, wherein each shoulder portion of the pair of shoulder portions comprises a substantially curved surface, and wherein each substantially curved surface has a curvature which substantially corresponds to a curvature of an external surface of the fluid transfer element.
 8. The capsule according to claim 1, further comprising a pair of posts arranged to provide an electrical connection between a main body of an electronic cigarette and the capsule.
 9. The capsule according to claim 8, wherein an interface is formed between the vaporizer housing and the pair of posts.
 10. The capsule according to claim 9, wherein the heating element comprises first and second ends, and wherein the first and second ends are located at the interface between the vaporizer housing and the pair of posts.
 11. The capsule according to claim 10, wherein the first and second ends of the heating element form lead wires which are compressed between the vaporizer housing and the pair of posts at the interface.
 12. The capsule according to claim 1, further comprising a first holder arranged to retain the vaporizer housing.
 13. The capsule according to claim 12, further comprising a second holder configured to receive the first holder.
 14. The capsule according to claim 13, wherein the second holder comprises at least one airflow inlet as part of the airflow passageway arranged to allow intake air to flow through the at least one aperture into the vaporizer housing.
 15. The capsule according to claim 14, wherein the airflow passageway forms part of the main vapor channel.
 16. An electronic cigarette comprising a main body and the capsule according to claim 1 wherein the main body comprises a power supply unit, electrical circuitry, and a capsule seating configured to connect with the capsule. 